The effects of the Affordable Care Act have been profound, even lifesaving, for some of those caught up in the nation's opioid-addiction crisis. But now, addicts and mentally ill people who gained access to treatment programs for the first time are worried about how that might change as President Donald Trump and Republicans in Congress try to make good on their promise to repeal and replace "Obamacare." Repeal could end coverage for 1.8 million people who have undergone addiction or mental health treatment. Richard Frank, a health economist at Harvard Medical School, said it could cut $5.5 billion in spending on such services.